Router (computer)

The internet protocol routers of the early 1970s were minicomputer, like this PDP 11, and were the size of a full sized refrigerator.

By the early 2000s routers had shrunk to the size of a book. Note, the four yellow ports, which use RJ-45 connectors to plug into nearby computers. An antennae indicates this router also accepts local connections wirelessly (WiFi). This is a DSL router. It is designed to manage a local network, an intranet, while connecting its computers to THE internet, using the rightmost white RJ-45.

In computer engineering a router is a special purpose computer that handles the data exchanges between the computers and devices on a network.

In the early 1970s the Defense Advanced Research Projects Agency sponsored a small committee of computer scientists to design a protocol, for computer networking, that would end up being called the "internet protocol".

Previously, when one computer connected to another computer, it was over a dedicated physical set of wires. When a computer needed to connect to multiple other computers, it would need a new set of dedicated physical wires, for each one. Computers that relied on an internet protocol router, could connect to any other computer on the network, using just one set of wires that connected to the router.

A program, running on a computer, on the network would make a request to connect to a service running on a different computer, using an universal resource locator, or URL, a form of address defined by the protocol. The routers, between their computer and the computer running the service, would seamlessly take care of the details.

See also

• internet
• intranet